Means for clamping and stretching flexible plates on printing-press cylinders



T. R. G. PARKER JEANS FOR CLAMPING AND STRETCHING FLEXIBLE PLATES ON PRINTING PRESS CYLINDERS Filedjlqch 1;, 1924 2 Sheets-Sheet 1 Aug. 1a, 1925. 1,550,452 E T. R. G. PARKER MEANS FOR CLAMPING AND STRETCHING FLEXIBLE PLATES ON PRINTING PRESS CYLINDERS Filed March 11 1924 2 Sheets-Sheet 2 Patented Aug. 18, 1925.

-UNITED STATES PATENT OFFICE.

THOMAS ROBERT GILLE'IT PARKER, 01B AL'I'BHQ'OEAM, ENGLAND, ASSIGNOB TO LIND- TYPE AND MACHINERY LIMITED, LONDON, ENGLAND, BRITISH LIMITED LIABILITY COMPANY.

MEANS FOR CLAMPING AND STBE'IGHING FLEXIBLE CYLINDERS.

PLATES on mm-r m Application filed larch 11, 1824. Serial No. 698,351.

To all whom it may concern: Y

Be it known that I, THoMas ROBERT- 'GILLE'I'I PARKER, a British subject, and resident of Linotype and Machinery Works, Altrincham, in the county of Chester, England, have invented new and useful Imrovements in Means for Clamping and gtretching Flexible Plates on Printing- PressCyllnders, of which the following is a specification. 5

This invention relates'to means for clamping and stretching flexible plates onprintingi press cylinders, and although especlally applicable for use in connection with the plate cylinders of web offset litho rota presses, it can be used in connectlon w t other types of. press.

In a web printing press, the gap of the plate cglinder, within which a plate clampmg an stretching device is located, must be of no greater width than the w1dth ot the margins at the top and bottom of a prmted page. For that reason it has heretofore been found somewhat difiicult to accommodate devices which will efliciently tighten the flexible plate about the perlphery .of the plate cylinder.

I The present invention provides a new or I improved construction which admits of the device being conveniently housed w1th1n the limited available accommodation, and by which the plate can be placed under any desired degree of tension. To that end it comprises means whereby the two ends of the plate (when the cylinder is clothed with only a single plate) or adjacent ends of dlfferent plates (when the cylinder is clothed with a plurality of plates) can be intersected within the gap, and drawn into the gap, for tightening said plate or platesupon the cylinder, in the direction of planes mtersecting within said gap.

To avoid undesirable circumlocution, the following description is restricted to an ar- 46 rangement wherein the press c linder 1s clothed with two printing plates, ut this is to be regarded merely as a convenient example, because the invention is equally applicable foruse in connection with one plate so or more than two plates.

v The invention will now be described by reference to the accompanying drawings plates themselves, with projections adapted which represent one constructional form of said invention, and in which Figure 1 is a side elevation partly broken away of a cylinder clothed with two plates; Flgure 2 is a v1ew of the cylinder drawn to a different scale partly in end elevation andpartly in transverse section, and

Figure 3 is a perspective view showing conventionally how the adjacent ends of the plates cross each other in intersecting planes.

According to this invention, as shown best in Figure 3, the flexible plate 1,is provided with a number of recesses or notches 2 and projections 3, located in such positions as to admit of the interposition between the projections 3 of the projections 4 of an adjacent plate 5, and vice versa these last named projections being produced by forming spaced recesses 6 in the same manner as is done in connection with the recesses 2 and projections 3; By these means the projections 3 of the plate 1 can be interposed between the projectlons 4 of the plate 5 and, can cross each other either at right angles as illustrated, or at any other angle as may be found most convenient.

.Within the press cylinder 7 just at the inner side of each gap 8,-therc are rovided two clamp bars 9, 10, each adjustab e, in the example illustrated, at right an les to the other in guides 11, 12 respective y, 'formed in guide plates 13. fast to the two ends of the press cylinder. Each of the clamp bars 9, 10, is fitted with a plate-clamping jaw 14, bolts or screws 15 for tightening said jaw on the plate 1 interposed between it-and the clamp ar, and springs 16 or other means 'for moving the jaw outwards from the clamp bar, when the bolts 15 are released.

As the adjustment of the two clamp bars 9, 10, is in directions intersecting each other at a point within the periphery of the cylinder 7 and it is desirable-that they engage the flexible plate 1 as near. as possible to said periphery the adjacent edges of these bars are formed, like the edges 0 the flexible tip be mi21tually interposed, as shown best in i re 11 each of the guide plates 13 there are journalled two screws 17 which engage with the clamp bars 9, 10, in such manner that when they are rotated, they move said bars cdgewise to tigthen or slacken the flexible plate 1 on the press cylinder 7.

The screws 17 appertaining to the two ends of each clamp bar 9, 10, are rotated in unison by helical gear wheels 18 fast to the former, and meshing with similar wheels 19 fast on a shaft 20 journalled in the plate cylinder 7, which-shaft can be rotated by a key or spanner applied to either of its squared ends, and when so rotated, efi'ects the tightening or loosening of the plate 1 around the cylinder 7.

Having described my invention, I declare that what I claim and desire to secure by Letters Patent is l. The combination with a rinting press cylinder, of flexible-plate c amping and stretching means located within a gap in the cylinder. and'adapted to draw into the gap,

in the direction of planes intersecting within the cylinder, intersecting plate ends presented at that gap.

2.- The combination with a printing press cylinder having a gap forthe reception of printing plate ends, of flexible-plate clamping and stretching means adapted to draw into the gap, in the direction of planes intersecting within the cylinder, intersectlng plate-ends presented at the gap, said means being located within the cyllnder beyond the line of intersection of said planes,

3. The combination with a printing press cylinder and flexible-plate clamping and stretching means located within a gap in the cylinder, of a pair of plate ends presented at the gap, and spaced projections on the said ends adapted to be mutually interposed.

4. The combination with a printing press cylinder having a gap adapted to receive printin plate ends, of two clamp bars located within the gap, spaced projections on the two bars ada ted to be mutually interposed, and a device adapted to move each such bar edgewise perpendicularly to the other bar.

5. The combination with a printing press cylinder having a gap adapted to receive printing plate ends, of two clamp bars located within the gap, a device at each end of the cylinder adapted to move each such bar edgewise perpendicularly to the other bar, and means whereby both of said devices can be 0 crated simultaneously from either end of t e cylinder.

6. The combination with a printing press cylinder having a gap ada ted to receive printing plate ends and a pan of plate ends presented at the gap, of spaced projections on the said ends ada ted to be mutually interposed, two clamp bars located within the gap adapted to clamp the interposed projections of the plate ends, spaced projections on the two bars adapted to be mutually interposed and a device adapted to move each clamp bar edgewise perpendicularly to the other clamp bar.

7. The combination with a printing press cylinder having a gap adapted to receive printing plate ends, of two clampbars located within the gap, spaced projections on the two bars adapted to be mutually interposed, a guide for each bar at each-end of the cylinder the guides'for one bar being located at right angles to those for the other bar, and a device at each end of the cylinder adapted to adjust each bar along its guide.

8. The combination with a printing press cylinder having a gap adapted to receive printing plate ends, of two clamp bars located within the gap, spaced projections on the two bars adapted to be mutually interposed, a guide for each bar at each end of the cylinder the guides for one bar being located at right angles to those for the other bar, a device at each end of the cylinder adapted to adjust each bar along its guide, and means whereby the two adjusting devices of each bar may be operated simultaneously. a

9. The combination with a printing press cylinder having a gap adapted to receive printing plate ends, of two clamp bars located within the gap, spaced projections on the two bars adapted to be mutually interposed, a guide plate at each end of the cylinder, guides in the said plates located at right-angles to each other and adapted to receive the ends of the respective bars, screws journalled in the guide plates and engaging the respective bars, and means adapted to rotate simultaneously the screws appropriate to each bar.

In testimony whereof I have afiixed my signature hereto.

THOMAS ROBERT GILLETT PARKER. 

